1. Field of the Invention
The present invention relates to a process for producing carbon black and an apparatus for producing the same. More particularly, it relates to a process for producing carbon black of a developed structure, and excellent electric conductivity and thermal conductivity which is produced from acetylene and an unsaturated hydrocarbon as sources and an apparatus for producing the same.
2. Description of the Prior Art
Usually, carbon black produced by the thermal decomposition of acetylene has a developed structure and has excellent characteristics such as electric conductivity, thermal conductivity and liquid adsorption and accordingly, the carbon black has been used for applications requiring such characteristics as electroconductive resins and rubbers and dry batteries etc.
It is especially important for the dry battery to have excellent liquid adsorption. The liquid of the commercially available acetylene type carbon black measured by the hydrochloric acid adsorption defined in Japanese Industrial Standard K 1469 is in a range of about 15.6 to 16.0 ml./5 g. In view of the requirement of the improved characteristics of a dry battery, a hydrochloric acid adsorption of greater than 17.0 ml./5 g. is required.
Various processes for producing such carbon black have been proposed. In Japanese Examined Patent Publication No. 30414/1968, improvement in liquid adsorption is achieved by using a furnace black produced by feeding additional acetylene to a carbon black produced after substantially most of a given amount of hydrocarbon for the carbon black product has been burned, and decomposing the acetylene. The product has, however, the same or lower liquid adsorption in comparison to conventional acetylene black. Although the amount of expensive acetylene is reduced, the improvement does not contribute to any improvement of the characteristics.